Carriage-return mechanism



April 8, 1930. R. G. THOMPSON CARRIAGE RETURN MECHANISM Original Filed Sept. 16 192b 2 Sheets-Sheet l April 8, 1930.

R. G. THOMPSON CARRIAGE RETURN MECH-NISM Original Filed Sept. 16 2 Sheets-Sheet lll/Ill L W SJW M Patented Apr. 8, 1930 UNITED STATES PATENT oEElcE RUSSELL G'. THOMPSON, 0F ROCHESTER, NEVSZ,y YORK, ASSIGNOR T0 ELECTROMATIC TYPEWRITERS, INC., OF ROOHESTER, NEW YORK, A CORPORATION F NEW YORK CARRIAGE-RETURN MECHANISM Application filed September 16, 1925, lSerial No. 56,737. Renewed March 6, 1929.

This invention relates to mechanism for returning the carriage of a typewriting machine, or the like, by power from a suitable sourcesuch as an electric motor. g The objectof the invention, in general, is to produce si'n'ple, compact, and efficient mechanism for the purpose in question. A more particular object of the invention isto produce a mechanism in whichthe operation is,y so far as possible, automatic, resulting from the momentary depression of a key or manual control member, and in which the return movement of. the carriage is arrested without jar, and the power mechanism is disconnected from the carriage automatically at the point determined by the usual adjustable margin stop. v

To theforegoing ends, the invention resides in the various features of construction and operation which will Abe pointed out in connection with the description of the illustrated embodiment of the invention, as these several features' are defined in the annexed claims.

`In the accompanying drawing Figs. 1 and 2 are, respectively, a plan-view and a frontelevation, showing the vmechanism of the present invention, together with portions of a typewriter in which it is embodied. Figs. 3-

and 4 are sectional views of details of the mechanism, on the lines 3 8 and 4 4 in Fig.A

2. Fig. 5 is a side-elevation of the mechanism as a whole. Fig. Gis a sectional front-elevation, on a larger scale than the preceding figures,A showing particularly the clutch, 'the winding drum and the clutch-operating mechanism. Fig. 7 is a partially sectional detail view of the pneumatic buffer, by which the motion of the` carriage is arrested ;y and Fig. 8 is aside-elevation of the cam-unit by which the clutch is thrown into 'operation The invention is-illustrated as .embodied in a typewriter of the well known Remington design, but only so much of the typewriter is shown as is necessary for an understanding of thek present invention. This machine has the usual frame 10, and platen-'roller 11, this roller'being supported in the usual manner on a carriage 12. The carriage is supported i' at the front by anti-friction rollers, moving against a front rail 13. The platen roller is rotated, for the purpose of line-spacing, by means of the usual pawl-m'echanismV 14, actuated by a handle at the front of the machine, this handle being that which is normally used to return the carriage by hand from. left to right.

The illustrated machine is one in .which all of the usual functions are performed by power derived from a motor, the keys being used merely to connect the various parts, such as the type-bars, tabulating stop, carriage return mechanism, etc., with the motordriven mechanism when these are to be actuated. The power mechanism comprlses a drive-shaft 16 which is journalled in a housing 17 at one side of the frame 10, near the bottom. This shaft carries a wormheel 18, driven by a worn1-19 which isrotate constantly by connection with the armatureshaft of an electric motor 20. A power-roller 21 is journalled transversely in the frame,

one end of the roller being supported, as i shown in Fig. 6, by engagement with the inner end of the drive-shaft 16. This roller has ya suitable frictional surface, providedl of the machine. A cam 26 is mounted to turn i on apivot 27,'between the depending arms 23 of the lever. This cam has a periphery l of the machine.

of spiral form, which is serrated to give ita good frictional hold against the surface of the roller 21 when in operation. A pin 28m, projecting from one side of the cam, is normally engaged b an arm 29 which swings upon a pivot 30 tween the lever members, and a spring 31, engaging the arm, presses it against the pin 28, thus tending to rotate the cam in a clockwise direct-ion and thus to bring its operative surface into engagement with the power-roller. Whenever this is permitted to occur, the rotation of the cam is continued by the action of the roller, and owing to the increasing radius of the cam the result is to rock the cam-lever.

The cam is normally heldout of operative engagement with the roller by means of'a stop-lever 32, which also swings upon the pivot 30. This'lever has, at its lower end, two lateral stop-lugs 33 and 34, which are vertically offset from each other, and which cooperate with a detent-lug 35 on the cam. The detent normally engages the stop-lug. 33 and prevents the spring-arm from rotating the cam. The upper end of the-stop-lever 1s provided with a lateral lug 36, which engages the forked rear end 37 of one of the key-levers When this lever is operated itl swings the stop-lever in a direction to'move the lug- 33 from left to right (as shown 1n Fig. 8) thus releasing the detent 35 and per- 'mitting the cam to be partially rotated, as above described, by the spring-arm 29. nearly complete rotation of the cam then oc, curs, with a swinging movement ofthe camlever, as above described, and the turning movement of the cam is finally arrested by engagement of the detent with the stop-lug 34. Upon the subsequent release and return of the key-lever the sto -lever moves back to its original position, t us permitting av slight partial rotation of the cam by which the/detent is again caused to engage the lug 33. Accordingly; at each depression and .release of the key-lever the cam makes a complete rotation and the cam-lever is caused to rock once forth and back.

The cam-mechanism just described does not constitute a feature of the present invention and need not, therefore, be more'fully shown and described, as it will be understood that any power means thrown. into operation by depression of a key may be used 'to perform the functions peculiar to the present invention. As shown in the drawings, the part 37 is the rear extremity of the key-lever 39 which controls the power-operated carriagereturn mechanism. This lever has an upward extension by which it is pivoted, at 40, on the frame of the machine, and a spring 41 holds the lever normally in`raised position. The lever is provided with the usual key 42 near its front end, and the movements of the lever are guided and limited by en agement with a slotted guide-bar 43, whic veatends across the front of the machine, and Whiclrserves a similar purpose in connection with the other keys of the machine.

The return movement of the carriage is produced by means comprising a flexible band, a drum upon which it is wound, and a clutch for rotating the drum. The drum 44, as shown in Fig. 6, is. mounted upon the power-shaft 16, but is normallyvfree to turn thereon. To connect it with the shaft when necessary, a clutch-plate 45 is mounted to slide upon the shaft, but is splined thereto so that it must turn with the shaft. This clutch-plate, when pressed to the left, engages the flat web of the drum so that the clutch-plate and the drum are held together frictionally, and the drum is thus forced to turn with the shaft. The axial movement of the clutch-plate is produced byltwo relatively movable discs 46 and 47, which embrace -and ride loosely upon the hub of the clutch-plate. A thrust-plate 48 is fixed to the outer end of the power-shaft by means of nuts 49, and'ball thrust-bearings are interposed between the discs 46 and 47, and the plates 45 and 48 respectively. Aforkedlever 50 has inwardlyldirected extremities 51, each of which rests loosely in a socket formed partly in each adjacent face of the discs 46v and 47.v

In Fig. 6 the clutch-*lever 50 is vertical, and'ili there is no end-thrust between the clutchmembers. If, however, theflev'er be rocked from itsvertical position, its extremities 51 act to pry the discs 46 and 47 away from each other, and'` pressure is through one of the ball-bearings tothe clutchplate, while the reaction of this pressure is taken by the other ball bearing, supported by the thrust-plate 48. l

To support the'clutch-lever, y ting the pivotal motion vjust described, it is also provided with outwardly directed extremities 52, which rest in sockets 53, formed at the ends of a' yoke 54, this yoke being fixed on-posts 55 projecting from the Kframe of the 110 machine.

The clutch-lever is moved by means of a l toggle, comprising a lever 56 which is pivoted on Va bracket 57 on the frame ofthe machine,

and a link 58 connecting one end of thev toggle- 115 lever 56 with an adjustable stud 59 at the upper end of the clutch-lever. The toggle is normally in -the broken position of Fig. 6,

being held in that position b v a spring 60 at- 100 tached to the clutch-lever. The opposite end of the toggle-lever is connected however, with the cam-levervof 8, by means of an adjustable link 38. Consequently, when the carriage-return key*v 42 is depressed, and the 125 cam-mechanism is thrown into operation, the toggle-lever is swung on its pivot so as to straighten the toggle, thus pushing the clutchlever into position to close the clutch, as above described. The toggle then acts to hold the 130 thus transmitted while permitclutch closed until it is broken again by other means, presently -to be described.. The rotation of the drum 44 winds up a fiexible band 103, which passes over a pulley 6l on the'frame of the machine, and is attached to a bracket 62, adjustably mounted on a rod 63. One end of this rod slides in a bearing 64, depending from the front rail 65 of the carriage. The other end of the rod 63 is pivoted to an arm 66 which is fixed to the shank of the handle 15, by which line spacing and carriage-return are performed manually. Accordingly, when the clutch rotates the drum and pulls the band, the first result is to slide the rod 63 toward vthe right, thus actuating the line-spacing .mechanism by which the platen is rotated. As soon, how-y ever, as the lost motion in this mechanism has been taken up,`fthfe carriage as a whole is moved toward the right. A spring 67, attached .to the end of the rod 63, returns it to normal position after tension upon the band is released. y

The carriage is provided, at its front, with the margin stops 68 and 69 usual in the Remington machine, these stops being adjustable upon the front rail 65 of the carriage and being retained in position by means of the usual y rack 70. The stationary stop, with which these margin stops cooperate, has a somewhat novel form in the present construction..

It comprises a backwardly and downwardly bent lug 71, lying in the path of the margin stops., and integral with a flat bar 72 which extends horizontally at the front of the frame. The right-hand end of this bar is slotted, and rides upon a pin*73 projecting from a bellcrank lever 74, `which is pivoted upon the frame. The narrow left-hand end \of the stop-bar 72 slides in a plate 75, mounted on the frame, so that when the return movement 4 of the carriage is substantially completed the I margin-stop 68, engaging the stop-lug71, moves the stop-bar 72 somewhat to the right, thus rocking the bell-crank lever 74. lThis lever is connected,.by means of a rod 76, with a second lever 77 pivoted, at one end, on a The'forward end of the lever 77 is connected, by a stem 79, with a diaphragm comprising a convex metal plate 80, and a disc 8 1 of leather or other'flexible material. This diaphragm-cooperates with' a metal shell 82 to form a pneumatic dash-pot or buffer, by which'the carriage is brought to rest without jar. The buffer is supportedon a bracket .83 constitutinga part of the machine, and it is provided, at the bottom, with a valve 84 which 'will lift to permit air to enter the buer freely. When the valve is closed, however, in consequence of pressure within the dashpot, the air can escape only through a small perforation in the middle of the valve.l l v When the return motion of the carriage is -arrested by the margin stop, the stop-bar 72 vmargin-release moves somewhat to the right and, .through the connections described, presses ithe diaphragm of thel buffer downwardly, thus bringing the carriage to rest without jar. Upon the subsequent feeding movement of the carriage from right to left, the stop-bar is released from engagement with the marginstop 68, and a spring 85 then raises the rod 76 and the diaphragm, causing the, buff-er to be filled again with air, vready for another operation.

At the end of the return movement of the carriage vit is necessary to throw the clutch out of 0peration and this is accomplished automatically. A lever 86 is pivoted on the bracket 57, and its rear end enters a hole in the toggle-lever 56. The forward end of lever 86 lies in position to be engaged and. depressed by a. stop-arm 87, mounted adjustably on the rod 76. This arm is embraced between nuts 88 which may be screwed up or down so as to clamp itin a positionsuch that it will engage the lever 86 just before the completion of the Adownward' movement of the rod. When thisoccurs, the lever 86 swings the toggle down far `enough to unlock it, and the spring 60 then restores the parts to the pojsition of Fig. 6, thus throwing the clutch out of operation. winding-drumk 44, tends-'constantly to rotate the drum in the direction to maintain a slight tension on the band 103. l This arrangement prevents the occurrence of slack in theband, in case the carriage is moved from left to right byhand. 'y l l When the carriage is'I returned for the length of a full line, or'any largepart there-` of, it ac uires a 'speed and momentum sufficient to ully depressfthe diaphragm of the buffer, asabove described. If,`however, the carriage-return key be pressed when the carriage has traveled only a short distance from its right-hand position, the space through which it will be returned before engagement of the margin stops may be so slight that 1t will not acquire sufficient momentum .to operi ate the buffer and disengage the clutch as described. Accordingly, provision is made for relieving the-carriage from the resistance of the buffer under these circumstances. A detent-arm 89 is pivoted at 90 on the front of the frame T0, and a. coiled spring 91, surrounding the pivot and engaging the arm, tends to swing its right-hand end rearwardly. This end is provided with a part 92, bent downwardly at its forward ed e, and with a lug 93 bent rearwardly from t e edge of the part 92. The narrow left-hand extremity 94 of the stop-bar 72 lies beneath the end of the arm 89, and is uided by engagement with a ever 96, which is pivoted to turn in a sleeve 97 on the front of the frame. The margin-release lever is slotted at the top toreceive the edge of the stop-bar 72, and the bar is normally pressed towards its rearward A coiled spring 104, within-the position by a spring-pressed rocker 98, which engages the front of the extremity 94. With these parts in the normal position, whenever the stop-bar is pressed to the right, by engagement of the margin stop 68 at the end of the return movement of the carriage, the extremity 94 moves to the right sufficiently to permit the'spring 91 to swing the detent arm 89 rearwardly and bring the lug 93 into position to engage the end of the part 94, and thus prevent the spring from returning the stop-bar fully to its left-hand position. Accordingly, the buffer diaphragm remains depressed at this time, and if the carriage be fed a few spaces to the left, and the return mechanism be then operated, the buffer will no longer be effective to resist the return movement to any substantial extent. It should be noted, however, that the parts are so adjusted as to permit the slight partial return movement of the buffer and the stopbar necessary to permit cooperation of the trip-arm 87 with the lever 86 by which the clutch is thrown out of operation.

The detent arm 89 is provided, at its rear edge, with a beveled projection which lies in the path of-'fnovement of the margin stop 68, and this projection is so located that it will be engaged by the margin stop after the carriage has been fed a suicient distance to the left, so that the detent-arm will be swung forwardlyand will disengage the stop-bar 72 and permit it to return fully to its left-hand position, so as to return the buffer to fully effective position.

It will be evident that in a machine provided both with an automatic carriage-return and with tabular-stop mechanism, it is undesirable that these two mechanisms be thrown into operation at the same time. Accordingly, the present machine is provided with an interlocking connection between the carriagereturn key 42, and the key by which the tabular stop is worked. This latter key 99 is shown at the left-hand side ofthe frame, being mounted on a key-lever 100, which may be connected, in any suitable manner with the tabular-stop mechanism. The interlocking in question is accomplished by means of a transverse lever 101 mounted on a central pivot 102 on the key-lever guide 43. The ends of the lever 101 lie beneath the two keylevers in question, so that when one of these levers is depressed the other cannotbe, owing to the elevation of the corresponding end of the lock-lever.

lVhen it is desired to release the carriage from either of the margin stops, this is done by depressing the margin-release lever 96 in the usual manner', which causes the stop-bar 7 2 to be swung forwardly, at its left hand end, thus moving the stop-lug 71 forwardly out of position for engagement with the stops 68 and 69.

Among other valuable features of the con- Vstruction herein described, it will be noted that no load is imposed upon the carriagereturn key 42, except that of throwing the power-actuating cam-unit into operation by swinging the stop-arm 32. All of the work of pressing the clutch-elements into engagement is then performed by the power-driven mechanism of the machine. Since the camunit as shown in Fig. 8 may be similar, in its general construction and mode of operation, with the corresponding mechanisms used to actuate the type-bars and other parts of the machine, it follows that the resistance encountered by the operator in depressing the carriage-return key may be precisely the same as in the case of any other key of the machine, and this has been found to be 'a valuable feature of operation, since it relieves the operator of the necessity of distinguishing between various keys with regard to the amount of force applied to them,

andthus permits the entire machine to be operated with force.V

Another valuable feature of the described construction resides in the fact that one or more additional line-spacing operations may be performed, by power, following a carriage-return movement. 'For this purpose it is necessary only to depress the key 42 again after the completion ofv the return movement. This causes the cam-mechanism to partially straighten the clutch-toggle, momentarily, thus causing upon the band v103 suiciently to operate the line spacer. Since the stop-arm 87 is in its depressed position at this time, the toggle is not permitted to move to locking position, however, so that the clutch is immediately released by the action of the spring 60. The limitation of the movement of the parts, by the stop-arm, during this operation is permitted by the yielding character of the rubber 21 which covers the power roller.

The novel features of the cam-mechanism shown in Fig. 8 are not claimed herein, as they have been disclosed and claimed in the applicants pending application, Serial No. 727,220, ined July 21, 1924.

The .invention claimed is:

1. In a typewriter or the like, the combination, with a carriage and power-operated means for returning the carriage, of a bufer for arresting the carriage at the end of the return movement a spring tending to return the buffer to fully operative position upon the subsequent feed movement of the carriage; and'means operating automatically to prevent such return of the buffer until the carriage has been fed-through a predetermined space.

2. In a power-operated typewriter, the combination with a carriage provided with line-spacing mechanism, a {iexible band connected with the carl-lage and said mechanism,

a light touch of minimum the clutch to pull a drum for winding the band to cause carriage return movements and line spacing movements, and a clutch for controlling the rotation of the drum, of clutch controlling mechanism for throwing the clutch into and out of operation', including means for retaining the clutch in operative position during the carriage-return movement, key-controlled power-mechanism operative, through said clutch controlling mechanism, to throw the clutch momentarily into Operative position, and means, controlled' by the carriage, for preventing the operation of the clutchretaining means when the carriage is at the end of its return movement.

RUSSELL G. THOMPSON. 

